Hi John-san, Thank you for your reply! It is UC3854B and I understand UC3854B doesn't require offset cancellation feature for internal current amplifier. My customer wants to cancel offset of external differential amplifier that is set between sense resistor…
Hi,
The UC3854B has been designed for use in systems with nominal AC line frequencies of 50Hz to 400Hz. It may be possible to use with 600Hz to 800Hz but the design information is just not available. What is your application for these unusual frequencies…
Part Number: UC3854B Hello,
Make UC385BDW board, and under testing.
But Several boards are abnormal output waveform as attached. Many others are normal output waveform.
Could you let me know why this kind of symptom occurred?
Is it related with…
Part Number: UC3854B Hello,
We’re having an issue with the UC3854B PWM controller. Specifically for the current amplifier section (pins 3, 4, 5), what is the input common mode operational range? The datasheet shows a CMMR Rejection spec. but not an…
Other Parts Discussed in Thread: UC3854B , UCC28070 , UCC28180 I am starting a design in which I would like to use the UC3854B IC. I am getting stuck at the point in the design where it says to calculate Rimo. My issue is the power levels I am trying…
Hi
Many customers use a 1N4148 type diode, the temperature range depends of course on the application but for most PFC's it does not go as low as -40C maybe -25C. The current in the diode is limited by the resistor from the RC filter so its usually…
Hi Renan,
The startup supply current of UC3854A and UC3854B is 300uA. But I didn't find this information of UC3854.
I am checking it and will get back to you soon.
Regards,
Teng
Thank you Harish. Appreciate the help.
Please see the attached example before and after comparison. Here we reduced the X-filter capacitance by 1/3 and the harmonic distortion is generally improved, except the 13th harmonic still fails by about 3mA…
